Pressure Shock-Induced Cooling Cycle

ABSTRACT

A supersonic cooling system operates by pumping liquid. Because the supersonic cooling system pumps liquid, the compression system does not require the use of a condenser. The compression system utilizes a compression wave. An evaporator of the compression system operates in the critical flow regime where the pressure in an evaporator tube will remain almost constant and then ‘jump’ or ‘shock up’ to the ambient pressure.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation and claims the prioritybenefit of U.S. patent application Ser. No. 12/732,131 filed Mar. 25,2010, which claims the priority benefit of U.S. provisional applicationNo. 61/163,438 filed Mar. 25, 2009 and U.S. provisional application No.61/228,557 filed Jul. 25, 2009. The disclosure of each of theaforementioned applications is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to cooling systems. The presentinvention more specifically relates to supersonic cooling systems.

2. Description of the Related Art

A vapor compression system as known in the art generally includes acompressor, a condenser, and an evaporator. These systems also includean expansion device. In a prior art vapor compression system, a gas iscompressed whereby the temperature of that gas is increased beyond thatof the ambient temperature. The compressed gas is then run through acondenser and turned into a liquid. The condensed and liquefied gas isthen taken through an expansion device, which drops the pressure and thecorresponding temperature. The resulting refrigerant is then boiled inan evaporator. This vapor compression cycle is generally known to thoseof skill in the art.

FIG. 1 illustrates a vapor compression system 100 as might be found inthe prior art. In the prior art vapor compression system 100 of FIG. 1,compressor 110 compresses the gas to (approximately) 238 pounds persquare inch (PSI) and a temperature of 190 F. Condenser 120 thenliquefies the heated and compressed gas to (approximately) 220 PSI and117 F. The gas that was liquefied by the condenser (120) is then passedthrough the expansion valve 130 of FIG. 1. By passing the liquefied gasthrough expansion value 130, the pressure is dropped to (approximately)20 PSI. A corresponding drop in temperature accompanies the drop inpressure, which is reflected as a temperature drop to (approximately) 34F in FIG. 1. The refrigerant that results from dropping the pressure andtemperature at the expansion value 130 is boiled at evaporator 140.Through boiling of the refrigerant by evaporator 140, a low temperaturevapor results, which is illustrated in FIG. 1 as having (approximately)a temperature of 39 F and a corresponding pressure of 20 PSI.

The cycle related to the system 100 of FIG. 1 is sometimes referred toas the vapor compression cycle. Such a cycle generally results in acoefficient of performance (COP) between 2.4 and 3.5. The coefficient ofperformance, as reflected in FIG. 1, is the evaporator cooling power orcapacity divided by compressor power. It should be noted that thetemperature and PSI references that are reflected in FIG. 1 areexemplary and illustrative.

A vapor compression system 100 like that shown in FIG. 1 is generallyeffective. FIG. 2 illustrates the performance of a vapor compressionsystem like that illustrated in FIG. 1. The COP illustrated in FIG. 2corresponds to a typical home or automotive vapor compressionsystem—like that of FIG. 1—with an ambient temperature of(approximately) 90 F. The COP shown in FIG. 2 further corresponds to avapor compression system utilizing a fixed orifice tube system.

Such a system 100, however, operates at an efficiency rate (e.g.,coefficient of performance) that is far below that of system potential.To compress gas in a conventional vapor compression system (100) likethat illustrated in FIG. 1 typically takes 1.75-2.5 kilowatts for every5 kilowatts of cooling power. This exchange rate is less than optimaland directly correlates to the rise in pressure times the volumetricflow rate. Degraded performance is similarly and ultimately related toperformance (or lack thereof) by the compressor (110).

Haloalkane refrigerants such as tetrafluoroethane (CH₂FCF₃) are inertgases that are commonly used as high-temperature refrigerants inrefrigerators and automobile air conditioners. Tetrafluoroethane havealso been used to cool over-clocked computers. These inert, refrigerantgases are more commonly referred to as R-134 gases. The volume of anR-134 gas can be 600-1000 times greater than the corresponding liquid.As such, there is a need in the art for an improved cooling system thatmore fully recognizes system potential and overcomes technical barriersrelated to compressor performance.

SUMMARY OF THE CLAIMED INVENTION

In a first claimed embodiment of the present invention, a supersoniccooling system is disclosed. The supersonic cooling system includes apump that maintains a circulatory fluid flow through a flow path and anevaporator. The evaporator operates in the critical flow regime andgenerates a compression wave. The compression wave shocks the maintainedfluid flow thereby changing the PSI of the maintained fluid flow andexchanges heat introduced into the fluid flow.

In a specific implementation of the first claimed embodiment, the pumpand evaporator are located within a housing. The housing may correspondto the shape of a pumpkin. An external surface of the housing mayeffectuate forced convection and a further exchange of heat introducedinto the compression system.

The pump of the first claimed embodiment may maintain the circulatoryfluid flow by using vortex flow rings. The pump may progressivelyintroduce energy to the vortex flow rings such that the energyintroduced corresponds to energy being lost through dissipation.

A second claimed embodiment of the present invention sets for a coolingmethod. Through the cooling method of the second claimed embodiment, acompression wave is established in a compressible fluid. Thecompressible liquid is transported from a high pressure region to a lowpressure region and the corresponding velocity of the fluid is greateror equal to the speed of sound in the compressible fluid. Heat that hasbeen introduced into the fluid flow is exchanged as a part of a phasechange of the compressible fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a vapor compression system as might be found in theprior art.

FIG. 2 illustrates the performance of a vapor compression system likethat illustrated in FIG. 1.

FIG. 3 illustrates an exemplary supersonic cooling system in accordancewith an embodiment of the present invention.

FIG. 4 illustrates performance of a supersonic cooling system like thatillustrated in FIG. 3.

FIG. 5 illustrates a method of operation for the supersonic coolingsystem of FIG. 3.

DETAILED DESCRIPTION

FIG. 3 illustrates an exemplary supersonic cooling system 300 inaccordance with an embodiment of the present invention. The supersoniccooling system 300 does not need to compress a gas as otherwise occursat compressor (110) in a prior art vapor compression system 100 likethat shown in FIG. 1. Supersonic cooling system 300 operates by pumpingliquid. Because supersonic cooling system 300 pumps liquid, thecompression system 300 does not require the use a condenser (120) asdoes the prior art compression system 100 of FIG. 1. Compression system300 instead utilizes a compression wave. The evaporator of compressionsystem 300 operates in the critical flow regime where the pressure in anevaporator tube will remain almost constant and then ‘jump’ or ‘shockup’ to the ambient pressure.

The supersonic cooling system 300 of FIG. 3 recognizes a certain degreeof efficiency in that the pump (320) of the system 300 does not (nordoes it need to) draw as much power as the compressor (110) in a priorart compression system 100 like that shown in FIG. 1. A compressionsystem designed according to an embodiment of the presently disclosedinvention may recognize exponential pumping efficiencies. For example,where a prior art compression system (100) may require 1.75-2.5kilowatts for every 5 kilowatts of cooling power, an system (300) likethat illustrated in FIG. 3 may pump liquid from 14.7 to 120 PSI with thepump drawing power at approximately 500 W. As a result of theseefficiencies, system 300 may utilize many working fluids, including butnot limited to water.

The supersonic cooling system 300 of FIG. 3 includes housing 310.Housing 310 of FIG. 3 is akin to that of a pumpkin. The particular shapeor other design of housing 310 may be a matter of aesthetics withrespect to where or how the system 300 is installed relative a facilityor coupled equipment or machinery. Functionally, housing 310 enclosespump 330, evaporator 350, and accessory equipment or flow pathscorresponding to the same (e.g., pump inlet 340 and evaporator tube360). Housing 310 also maintains (internally) the cooling liquid to beused by the system 300.

Housing 310, in an alternative embodiment, may also encompass asecondary heat exchanger (not illustrated). A secondary heat exchangermay be excluded from being contained within the housing 310 and system300. In such an embodiment, the surface area of the system 300—that is,the housing 310—may be utilized in a cooling process through forcedconvection on the external surface of the housing 310.

Pump 330 may be powered by a motor 320, which is external to the system300 and located outside the housing 310 in FIG. 3. Motor 320 mayalternatively be contained within the housing 310 of system 300. Motor320 may drive the pump 330 of FIG. 3 through a rotor drive shaft with acorresponding bearing and seal or magnetic induction, wherebypenetration of the housing 310 is not required. Other motor designs maybe utilized with respect to motor 320 and corresponding pump 330including synchronous, alternating (AC), and direct current (DC) motors.Other electric motors that may be used with system 300 include inductionmotors; brushed and brushless DC motors; stepper, linear, unipolar, andreluctance motors; and ball bearing, homopolar, piezoelectric,ultrasonic, and electrostatic motors.

Pump 330 establishes circulation of a liquid through the interior fluidflow paths of system 300 and that are otherwise contained within housing310. Pump 330 may circulate fluid throughout system 300 through use ofvortex flow rings. Vortex rings operate as energy reservoirs wherebyadded energy is stored in the vortex ring. The progressive introductionof energy to a vortex ring via pump 330 causes the corresponding ringvortex to function at a level such that energy lost through dissipationcorresponds to energy being input.

Pump 330 also operates to raise the pressure of a liquid being used bysystem 300 from, for example, 20 PSI to 100 PSI or more. Pump inlet 340introduces a liquid to be used in cooling and otherwise resident insystem 300 (and contained within housing 310) into pump 330. Fluidtemperature may, at this point in the system 300, be approximately 95 F.

The fluid introduced to pump 330 by inlet 340 traverses a primary flowpath to nozzle/evaporator 350. Evaporator 350 induces a pressure drop(e.g., to approximately 5.5 PSI) and phase change that results in a lowtemperature. The cooling fluid further ‘boils off’ at evaporator 350,whereby the resident liquid may be used as a coolant. For example, theliquid coolant may be water cooled to 35-45 F (approximately 37 F asillustrated in FIG. 3). As noted above, the system 300 (specificallyevaporator 350) operates in the critical flow regime thereby allowingfor establishment of a compression wave. The coolant fluid exits theevaporator 350 via evaporator tube 360 where the fluid is ‘shocked up’to approximately 20 PSI because the flow in the evaporator tube 360 isin the critical regime. In some embodiments of system 300, thenozzle/evaporator 350 and evaporator tube 360 may be integrated and/orcollectively referred to as an evaporator.

The coolant fluid of system 300 (having now absorbed heat fordissipation) may be cooled at a heat exchanger to assist in dissipatingheat once the coolant has absorbed the same (approximately 90-100 Fafter having exited evaporator 350). Instead of an actual heatexchanger, however, the housing 310 of the system 300 (as was notedabove) may be used to cool via forced convection. FIG. 4 illustratesperformance of a supersonic cooling system like that illustrated in FIG.3.

FIG. 5 illustrates a method of operation 500 for the supersonic coolingsystem 300 of FIG. 3. In step 510, a gear pump 330 raises the pressureof a liquid. The pressure may, for example, be raised from 20 PSI to inexcess of 100 PSI. In step 520, fluid flows through thenozzle/evaporator 350. Pressure drop and phase change result in a lowertemperature in the tube. Fluid is boiled off in step 530.

Critical flow rate, which is the maximum flow rate that can be attainedby a compressible fluid as that fluid passes from a high pressure regionto a low pressure region (i.e., the critical flow regime), allows for acompression wave to be established and utilized in the critical flowregime. Critical flow occurs when the velocity of the fluid is greateror equal to the speed of sound in the fluid. In critical flow, thepressure in the channel will not be influenced by the exit pressure andat the channel exit, the fluid will ‘shock up’ to the ambient condition.In critical flow the fluid will also stay at the low pressure andtemperature corresponding to the saturation pressures. In step 540,after exiting the evaporator tube 360, the fluid “shocks” up to 20 PSI.A secondary heat exchanger may be used in optional step 550. Secondarycooling may also occur via convection on the surface of the system 300housing 310.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. The descriptions are not intended to limit the scope of theinvention to the particular forms set forth herein. Thus, the breadthand scope of a preferred embodiment should not be limited by any of theabove-described exemplary embodiments. It should be understood that theabove description is illustrative and not restrictive. To the contrary,the present descriptions are intended to cover such alternatives,modifications, and equivalents as may be included within the spirit andscope of the invention as defined by the appended claims and otherwiseappreciated by one of ordinary skill in the art. The scope of theinvention should, therefore, be determined not with reference to theabove description, but instead should be determined with reference tothe appended claims along with their full scope of equivalents.

1. A pressure shock-induced cooling method, comprising: a firstisenthalpic step, the first isenthalpic step comprising a shock-inducedincrease in pressure of a working fluid.
 2. The method of claim 1,further comprising a second isenthalpic step, the second isenthalpicstep comprising a decrease in pressure of the working fluid.
 3. Themethod of claim 2, wherein the second isenthalpic step further comprisesan increase in pressure of the working fluid prior to the decrease inpressure of the working fluid.
 4. The method of claim 3, wherein theincrease in pressure of the working fluid is to a pressure of about 1bar or higher.
 5. The method of claim 4, wherein the increase inpressure of the working fluid is to a pressure of about 10 bar orhigher.
 6. The method of claim 3, wherein the increase in pressure ofthe working fluid is facilitated by a pump.
 7. The method of claim 2,wherein the decrease in pressure of the working fluid is to a pressureless than about 0.2 bar.
 8. The method of claim 2, wherein the decreasein pressure of the working fluid is facilitated by an evaporator.
 9. Themethod of claim 2, further comprising heating the working fluid betweenthe first and second isenthalpic steps.
 10. The method of claim 9,wherein the heating of the working fluid includes heat transfer from aheat exchanger to the working fluid.
 11. The method of claim 2, furthercomprising cooling the working fluid between the first and secondisenthalpic steps.
 12. The method of claim 11, wherein the cooling ofthe working fluid includes heat transfer from the working fluid to aheat exchanger.
 13. The method of claim 1, wherein the working fluid isa liquid.
 14. A method for cooling and heating a fluid circulatedthrough a fluid flow path, the method comprising: isenthalpicallydecreasing the pressure of the fluid; increasing the temperature of thefluid; insenthalpically increasing the pressure of the fluid, whereinthe increase in pressure is shock-induced; and decreasing thetemperature of the fluid.
 15. The method of claim 14, wherein the fluidis circulated using a pump.
 16. The method of claim 14, wherein thetemperature is increased in an evaporator.
 17. The method of claim 14,wherein the fluid undergoes an increase in pressure prior to theisenthalpic decrease in pressure.
 18. The method of claim 17, whereinthe increase in pressure is isenthalpic.
 19. The method of claim 17,wherein the increase in pressure is to a pressure of about 1 bar orhigher, and the decrease in pressure is to a pressure below about 0.2bar.
 20. The method of claim 14, wherein the isenthalpic decrease inpressure of the fluid occurs at a critical flow rate.